feat(task): add task templates for reusable task definitions by jdx · Pull Request #7873 · jdx/mise

jdx · 2026-01-28T15:05:26Z

Summary

This PR adds support for task templates that allow defining reusable task definitions which can be extended by tasks via the extends field. This enables DRY task definitions in monorepos and projects with similar task patterns.

Key features:

Templates are defined in [task_templates.*] sections of mise.toml
Tasks can extend templates using extends = "template-name"
Templates support colon-namespacing: python:build, rust:test, etc.
Smart merge semantics:
- run, depends, sources, outputs: local overrides completely
- tools, env: deep merge (local values override template values)
- Other fields: local overrides if set
Requires experimental = true in settings

Example usage:

[settings]
experimental = true

[task_templates."python:build"]
description = "Build a Python project"
run = "uv build"
tools = { python = "3.12", uv = "latest" }
env = { PYTHONPATH = "src" }

[tasks.build]
extends = "python:build"
env = { DEBUG = "1" }  # merged with template env

Test plan

🤖 Generated with Claude Code

Note

Adds experimental task templates to enable DRY task definitions and inheritance.

New task_templates in mise.toml with extends support and defined merge semantics; implements TaskTemplate and Task::merge_template
Task loading pipeline updated to collect/resolve templates across config hierarchy; functions now accept templates and error if missing or if experimental is off
generate task-docs updated to include template resolution
Docs: new docs/tasks/templates.md, sidebar/nav entries, and monorepo references
Tests: comprehensive e2e for extends/merging/errors/namespacing/experimental flag and unit tests for merge logic

^{Written by Cursor Bugbot for commit d2a9296. This will update automatically on new commits. Configure here.}

Add support for task templates that can be extended by tasks via the `extends` field. This enables DRY task definitions in monorepos and projects with similar task patterns. Templates are defined in [task_templates.*] sections and can provide default values for run, tools, env, depends, and other task fields. Tasks can extend templates and override specific fields as needed. Merge semantics: - run, depends, sources, outputs: local overrides completely - tools, env: deep merge (local values override template) - Other fields: local overrides if set Requires experimental = true to use. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Copilot

Pull request overview

This PR adds support for task templates, allowing users to define reusable task definitions that can be extended by tasks via the extends field. This feature enables DRY (Don't Repeat Yourself) principles in task definitions, particularly useful in monorepos and projects with similar task patterns.

Changes:

Introduces TaskTemplate struct with same fields as Task for defining reusable configurations
Implements template resolution with smart merge semantics (deep merge for tools/env, complete override for run/depends/sources/outputs)
Adds experimental flag requirement for using the extends feature
Templates support colon-namespacing (e.g., python:build, rust:test)

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/task/task_template.rs	New file containing `TaskTemplate` struct and `merge_template` implementation with comprehensive unit tests
src/task/mod.rs	Adds `extends` field to `Task` struct and exports `TaskTemplate`
src/config/mod.rs	Implements template collection, resolution, and integration into task loading pipeline
src/config/config_file/mod.rs	Adds `task_templates()` trait method to `ConfigFile`
src/config/config_file/mise_toml.rs	Implements `TaskTemplates` type and deserialization logic
src/cli/generate/task_docs.rs	Updates task documentation generation to handle templates
e2e/tasks/test_task_templates	Comprehensive E2E tests covering all template features and edge cases

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot · 2026-01-28T15:06:20Z

            redactions: self.redactions.clone(),
            plugins: self.plugins.clone(),
            tasks: self.tasks.clone(),
+            task_templates: self.task_templates.clone(),


The task_templates field in the Clone implementation lacks test coverage. Consider adding a test that verifies cloning a MiseToml instance with task templates preserves the templates correctly.

Copilot · 2026-01-28T15:06:20Z

+    // Iterate in reverse order (global -> local) so child directories override parent configs
+    for cf in config_files.values().rev() {


The comment states 'Iterate in reverse order (global -> local) so child directories override parent configs', but .rev() on values() actually iterates from local to global (since values() already returns an iterator in insertion order, which is global->local in ConfigMap). Either the comment is incorrect or the iteration order is backwards. Consider clarifying or fixing this.

Suggested change

// Iterate in reverse order (global -> local) so child directories override parent configs

for cf in config_files.values().rev() {

// Iterate from global to local so later (child) configs overwrite earlier (parent) templates

for cf in config_files.values() {

Copilot · 2026-01-28T15:06:21Z

+
+assert "mise run build" "cargo build"
+
+echo '' >mise.toml


The test cleanup at the end uses echo '' >mise.toml which creates a file with a newline. Consider using rm -f mise.toml or true >mise.toml for cleaner test isolation, as the empty file with a newline could affect subsequent tests.

Suggested change

echo '' >mise.toml

rm -f mise.toml

- Add new docs/tasks/templates.md with comprehensive documentation - Update docs/tasks/index.md to reference templates - Update docs/tasks/monorepo.md to show template usage in monorepos - Add Task Templates to sidebar navigation Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Use <code v-pre> to escape Tera template syntax that was being interpreted as Vue template syntax by VitePress. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

jdx · 2026-01-28T15:24:55Z

bugbot run

cursor

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{Bugbot Autofix is OFF. To automatically fix reported issues with Cloud Agents, enable Autofix in the Cursor dashboard.}

Boolean fields (quiet, hide, raw) in Task use `bool` not `Option<bool>`, so we cannot distinguish between "not set" (defaults to false) and "explicitly set to false". Remove merge logic for these fields to avoid overriding a task's explicit `false` value with a template's `true`. Users must explicitly set these fields in their task if needed. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

github-actions · 2026-01-28T15:53:30Z

Hyperfine Performance

`mise x -- echo`

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
`mise-2026.1.8 x -- echo`	19.1 ± 0.2	18.6	21.7	1.00
`mise x -- echo`	19.3 ± 0.2	18.9	20.5	1.01 ± 0.02

`mise env`

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
`mise-2026.1.8 env`	18.5 ± 0.5	18.0	23.5	1.00
`mise env`	18.8 ± 0.3	18.2	22.3	1.02 ± 0.03

`mise hook-env`

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
`mise-2026.1.8 hook-env`	18.8 ± 0.3	18.4	24.6	1.00
`mise hook-env`	19.1 ± 0.2	18.6	20.3	1.01 ± 0.02

`mise ls`

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
`mise-2026.1.8 ls`	16.7 ± 0.2	16.2	17.4	1.00
`mise ls`	17.0 ± 0.2	16.5	19.0	1.02 ± 0.02

`xtasks/test/perf`

Command	mise-2026.1.8	mise	Variance
install (cached)	108ms	108ms	+0%
ls (cached)	65ms	65ms	+0%
bin-paths (cached)	69ms	69ms	+0%
task-ls (cached)	278ms	⚠️ 2263ms	-87%

⚠️ Warning: task-ls cached performance variance is -87%

@jdx

### 🚀 Features - **(doctor)** add backend mismatch warnings by @jdx in [#7847](#7847) - **(http)** add rename_exe support for archive extraction by @jdx in [#7874](#7874) - **(http)** send x-mise-ci header for CI environment tracking by @jdx in [#7875](#7875) - **(install)** auto-install plugins from [plugins] config section by @jdx in [#7856](#7856) - **(registry)** add vercel by @mikecurtis in [#7844](#7844) - **(task)** support glob patterns in task_config.includes by @jdx in [#7870](#7870) - **(task)** add task templates for reusable task definitions by @jdx in [#7873](#7873) ### 🐛 Bug Fixes - **(backend)** change registry mismatch log from info to debug by @jdx in [#7858](#7858) - **(ci)** use squash merge for auto-merge-release workflow by @jdx in [7e5e71e](7e5e71e) - **(ci)** remove --auto flag to merge immediately when CI passes by @jdx in [23ed2ed](23ed2ed) - **(github)** select platform-matching provenance file for SLSA verification by @jdx in [#7853](#7853) - **(go)** filter out version "1" from available versions by @jdx in [#7871](#7871) - **(install)** skip CurDir components when detecting archive structure by @jdx in [#7868](#7868) - **(pipx)** ensure Python minor version symlink exists for postinstall hooks by @jdx in [#7869](#7869) - **(registry)** prevent duplicate -stable suffix in Flutter download URLs by @jdx in [#7872](#7872) - **(task)** pass env to usage parser for env-backed arguments by @jdx in [#7848](#7848) - **(task)** propagate MISE_ENV to child tasks when using -E flag by @jdx in [06ee776](06ee776) - **(vfox-dotnet)** use os.execute() to fix Windows installation by @prodrigues1912 in [#7843](#7843) ### 📚 Documentation - update cache-behavior with env_cache information by @jdx in [#7849](#7849) ### ◀️ Revert - remove task inheritance from parent configs in monorepos by @jdx in [#7851](#7851) - Revert "fix(ci): remove --auto flag to merge immediately when CI passes" by @jdx in [0606187](0606187) ### 📦 Registry - add mago ([aqua:carthage-software/mago](https://github.com/carthage-software/mago)) by @scop in [#7845](#7845) ### Chore - **(ci)** auto-merge release branch into main daily at 4am CST by @jdx in [#7852](#7852) ### New Contributors - @mikecurtis made their first contribution in [#7844](#7844) - @prodrigues1912 made their first contribution in [#7843](#7843)

Copilot AI review requested due to automatic review settings January 28, 2026 15:05

Copilot AI reviewed Jan 28, 2026

View reviewed changes

jdx and others added 5 commits January 28, 2026 09:08

docs(task): remove error handling section from templates doc

f71dd60

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs(task): add file task templates to future enhancements

a7b84a8

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs(task): fix Vue template syntax escaping in templates doc

78aaf7d

Use <code v-pre> to escape Tera template syntax that was being interpreted as Vue template syntax by VitePress. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

[autofix.ci] apply automated fixes

35f7c09

[autofix.ci] apply automated fixes (attempt 2/3)

4b81bf7

cursor Bot reviewed Jan 28, 2026

View reviewed changes

Comment thread src/task/task_template.rs

jdx enabled auto-merge (squash) January 28, 2026 15:48

jdx merged commit 81589bd into main Jan 28, 2026
34 checks passed

jdx deleted the feat/task-templates branch January 28, 2026 15:52

mise-en-dev mentioned this pull request Jan 28, 2026

chore: release 2026.1.9 #7846

Merged

BrewTestBot mentioned this pull request Jan 28, 2026

mise 2026.1.9 Homebrew/homebrew-core#264909

Merged

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

feat(task): add task templates for reusable task definitions#7873

feat(task): add task templates for reusable task definitions#7873
jdx merged 8 commits intomainfrom
feat/task-templates

jdx commented Jan 28, 2026 •

edited by cursor Bot

Loading

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI Jan 28, 2026

Uh oh!

Copilot AI Jan 28, 2026

Uh oh!

Copilot AI Jan 28, 2026

Uh oh!

jdx commented Jan 28, 2026

Uh oh!

cursor Bot left a comment

Uh oh!

Uh oh!

Uh oh!

github-actions Bot commented Jan 28, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

		// Iterate in reverse order (global -> local) so child directories override parent configs
		for cf in config_files.values().rev() {

Uh oh!

Conversation

jdx commented Jan 28, 2026 • edited by cursor Bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Test plan

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Copilot AI Jan 28, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Jan 28, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Jan 28, 2026

Choose a reason for hiding this comment

Uh oh!

jdx commented Jan 28, 2026

Uh oh!

cursor Bot left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

github-actions Bot commented Jan 28, 2026

Hyperfine Performance

mise x -- echo

mise env

mise hook-env

mise ls

xtasks/test/perf

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

jdx commented Jan 28, 2026 •

edited by cursor Bot

Loading

`mise x -- echo`

`mise env`

`mise hook-env`

`mise ls`

`xtasks/test/perf`